Josh Gottheimer, a Democrat considering a run against U.S. Rep. Scott Garrett (R-5th Dist.) in 2016, is showing that he's serious about challenging an incumbent who Democrats have fantasized about toppling for years.

Gottheimer raised about $412,000 over the last three months for his exploratory committee, according to a copy of a campaign finance filing obtained by The Auditor -- a huge haul for a first-time candidate who hasn't even declared his candidacy against the well-entrenched Garrett. Combined with Gottheimer's first quarter, he's raised $630,000.

Then again, the 40-year-old Wyckoff resident is no political neophyte. He was a speechwriter for former President Bill Clinton, followed by stints with the presidential campaigns of General Wesley Clark and John Kerry. He worked for the Federal Communication Commission before becoming a corporate strategist for Microsoft.

And his filing reflects those roots.

Gottheimer's donors include many people from the Clinton White House, including two chiefs of staff: Thomas "Mack" McLarty and Erskine Bowles. Paul Begala, a strategist for President Clinton and pundit. and Sandy Berger, former national security advisor to President Clinton, are also on the list. Patti Solis Doyle, a longtime Hillary Clinton aide who managed the first part of her 2008 presidential campaign, maxed out to Gottheimer and hosted a May fundraiser for him that produced many of the big name donations.

Obama administration veterans are represented, including Obama's former body man, Reggie Love, and former White House counsel Gregory Craig.

Other notables include Laurene Powell Jobs, the widow of Apple co-founder Steve Jobs, and movie producer Todd Lieberman, whose credits include the 2011 Muppets movie and the 2010 film The Fighter.

Likely New Jersey 2017 gubernatorial candidates Steve Fulop and Phil Murphy have both given to Gottheimer, as has U.S. Sen. Cory Booker's leadership PAC.

Gottheimer declined to comment.

This is not the first time Democrats have pledged a competitive race against Garrett, who is by far New Jersey's most conservative congressman. Roy Cho, who challenged him in 2014, ran an energetic campaign that raised more than $1 million and at one point came within 5 points of Garrett in a poll. But Garrett unleashed more than $2 million in spending to bury Cho, and won the election by 13 points (Cho is now among Gottheimer's donors).

That, however, was an off-year election. And with Gottheimer's connections to national Democrats and 2016 having a presidential race at the top of the ticket that promises high turnout, Democrats think next year could finally, actually, truly be different.

Gottheimer's candidacy has caught the attention of the Democratic Congressional Campaign Committee, whose chairman, U.S. Rep. Ben Ray Lujan (D-New Mexico), has contributed and sent out a fundraising email on his behalf.